Modern communication systems require ever increasing bandwidths. To provide the required bandwidths, optical communication technology that makes use of optical fibers has become essential. The devices required by an optical network include not only optical fibers, but also lasers for converting electrical signals into optical signals, light amplifiers, light attenuators, and numerous other electronic and optoelectronic devices.
Optical fibers provide the waveguide function in most optical networks. Hence, imparting other network functions to optical fibers is highly desirable. Devices such as amplifiers, filters, and optical delay lines have all been implemented in optical fibers. In the following discussion, optoelectronic devices that utilize optical fibers for functions in addition to the waveguide function will be referred to as “functional optical fibers.”
To accommodate the length of optical fiber in an optoelectronic device having a functional optical fiber, the optical fibers are wound around a cylindrical or spool-shaped base. The material that makes up a conventional functional optical fiber has poor mechanical strength. In addition, bending or twisting of a functional optical fiber can create non-uniform stress in the optical fiber, which produces birefringence. The birefringence often causes a change in the direction of polarization or to transmission losses. Accordingly, the fiber usually cannot be bent to a radius of curvature of less than about 20 cm in conventional functional optical fibers. This results in greater bulk and increased cost.
For the purposes of this discussion, the term “optoelectronic circuit” is used to refer to a circuit that may include both an electronic circuit and an optical circuit. An optical circuit means a device that includes a path for conveying an optical signal between two points that are separated in space. An “optoelectronic device” refers to any device that includes an optoelectronic circuit.
Broadly, it is the object of the present invention to provide an improved optoelectronic device.
This and other objects of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention and the accompanying drawings.